Interior Advice & roll cage advice

#1

im currently build a spec e30 out of a 1989 325is i tore out all the interior and left the dash as is and the roof i also took aluminum sheet metal and fitted it on the doors to give it that racer look and give the roll cage more room when i get it in… i have heard from people that i need to take apart the sunroof and have it welded to the roof and that taking out the interior part of the roof will greatly help my center of gravity…could someone give me advice on what i could do?

i want to get a roll cage welded in but i dont know of a shop that specializes in race car roll cages in the tampa bay area can someone help me?

#2

You’ll want to remove the sunroof ‘cassette’ and all things associated with it. The original roof panel is a bit fussy to try to fit in there by itself. It leaves a pretty large gap around the perimeter where the gasket used to be and welding it in is tricky. A far simpler solution is to just rivet a panel right over the opening, overlap an inch or two onto the roof. Use double or triple beads of caulk to seal it from leakage. It’s not the prettiest solution, but then you’re trying to win races, not car show trophies. :stuck_out_tongue: There are several threads on here discussing sunroof removal and closure, use the search tool.

For a cage source you may try posting on the Grassroots Motorsports forum.

#3

Make your life easy, leave it in.
The 3-5pounds of weight will not make a difference. I’ve got three cars and I can do the same lap times in the one that is speced-out versus the other 2 cars that still have power windows and power roof.

Perhaps I should learn to drive, but it makes no difference.

Regards, Robert Patton

#4

yea i kept the power windows in because ill be driving the car to the track. but i will take out the rest of the interior and see how the sunroof looks and see if i can find a way to improvise a solution.

#5

Patton wrote:

[quote]Make your life easy, leave it in.
The 3-5pounds of weight will not make a difference. I’ve got three cars and I can do the same lap times in the one that is speced-out versus the other 2 cars that still have power windows and power roof.

Perhaps I should learn to drive, but it makes no difference.[/quote]
The power windows are one thing, and the sunroof is another. Removing the sunroof takes off close to 40lb that is up high. And that is a good thing. It also increases head room and lets the main hoop be higher which is also good.

Robert would be fast in anything with or without wheels, so discount what he says!

#6

Jim, is that junk 40 pounds?

If so, I stand corrected and rip it out.

But, I still can wheel the 8 Ball the same as the taxi.

Let’s ask Skeen. I think his is still in?

RP

#7

yea taking it out does sound pretty good. I guess my next question is whats the best way of doing it and closing up the hole. if you guys have any pics so i can get some ideas i would greatly appreciate it.:slight_smile:

#8

Patton wrote:

[quote]Jim, is that junk 40 pounds?

If so, I stand corrected and rip it out.

But, I still can wheel the 8 Ball the same as the taxi.

Let’s ask Skeen. I think his is still in?[/quote]
Memory is a tenuous thing. But that is what I remember getting for the weight of the sunroof when I built the 96 two years ago. I’ll get a new number from the new car (and write it down this time).

Since the wreck I’ve come up with a list of things that I’m going to do differently on the new car. Anyone building a car should give consideration to “lessons learned”. At present that list looks like:

NASCAR door bars
The door bars mean you have to have removable windows, but they dramatically improve the safety zone around the driver.

Foot protection
There was a good bit of intrusion into the passenger foot well in the wreck. Foot protection will reduce the chance of injury if that happens on the driver’s side.

Battery relocated to between the shock towers
In the OE configuration the battery is located in the rear crush zone. This means that there is a chance of short to the battery in a wreck, which could cause a fire.

Full cradle for the fire bottle
The fire bottle slid free of one retainer and almost free of the second. I’ll build a four way cradle for the new car as I don’t want it becoming a missile, and if I need it I want it to work.

Racetech Viper seat
A halo seat is a very good thing! And the extended lateral support of the Viper helps keep you in place. At some point in the incident I hit the center net hard enough to cause the quick release to open (distorted the latch). So a better seat with extended support yields better protection.

HANS specific harness
The harness has to be replaced (or re-certified). A HANS specific harness is slightly better that a plain 3" harness, so I’ll go that route for a new harness.

#9

jlevie wrote:

[quote]Battery relocated to between the shock towers
In the OE configuration the battery is located in the rear crush zone. This means that there is a chance of short to the battery in a wreck, which could cause a fire.[/quote]

Hate to be that guy, but you can’t do that within the current ruleset.

#10

There’s some old threads that go into lots of detail. The only tricky part is the 6? spot welds from the B pillars forward. If you find yourself about to cut thru a B pillar, pause and say to yourself “this sounds like a bonehead Scott move”.

The harder part is plugging the sunroof hole. The elegant solution is to separate the layers of sunroof and then fasten it back into place. The lousy solution is to not separate the sunroof layers and fasten it back into place. It’s lousy because the sunroof is still pretty heavy if you don’t skin it.

Neither of those are easy because you have to rig up something that will hold the sunroof in place. I burned thru all sorts of ideas on that, all of which failed.

The middle solution is to cut a piece of sheetmetal and slap ito on your roof, which was my ultimate solution. This is the easy solution.

All of this is in old threads.

#11

TheRedBaron wrote:

[quote]jlevie wrote:

[quote]Battery relocated to between the shock towers
In the OE configuration the battery is located in the rear crush zone. This means that there is a chance of short to the battery in a wreck, which could cause a fire.[/quote]

Hate to be that guy, but you can’t do that within the current ruleset.[/quote]

Agree with Craig, where have you seen this done? Using the same logic of it being a crush zone; so is the front end. Seems to me it would be more dangerous to have it in the front verses the rear.

#12

I think he’s referring to REAR shock towers.

Sounds against the rules to me. That’s a hunk of weight that’s being moved around… I don’t know how much difference it would make, but could open a can of worms. (For the record, it sounds like a good idea, though!)

#13

yea the sheet metal solution to the roof sounds most logical. i already have a Recaro seat with the extended head and neck support, its alot more secure safer feeling for me compared to the seats i sat in, in formula 2000 and skip barber. lol. would removing the entire A/C system be a smart way to cut some weight out of the car? or should i just take out the a/c compressor under the hood?

#14

RSchwyn wrote:

I’d remove all AC components that are in the engine bay, and remove the dash AC components if the dash is out. Also might want to remove the power steering pump and loop the hose to/from steering box.

A number of coolant hoses can be plugged and cut too.
Rear of head -> Thermostat body (This has T to heater box)
Left side of block -> Thermostat body
Intake manifold -> Thermostat body (I think)

#15

shifter11 wrote:

[quote]I think he’s referring to REAR shock towers.
[/quote]

Technically, those are the only shock towers in the car. Those front ones are strut towers. :stuck_out_tongue:

Steve D.

PS - I like the fire bottle in the trunk. It helps put some more weight over the right rear and it can’t beat you in the head in case it breaks loose.

#16

true and also true.

#17

There are advantages and disadvantages to both locations. With the bottle where I had it mounted it is easy to verify (by feel if need be) that the safety pin is out. And if the pull handle didn’t work I could fire the bottle directly.

I’d think that I’d need uber long pull cables if I mounted the bottle in the trunk. Obviously that isn’t a problem for an electrical fire system.

#18

jlevie wrote:

[quote]There are advantages and disadvantages to both locations. With the bottle where I had it mounted it is easy to verify (by feel if need be) that the safety pin is out. And if the pull handle didn’t work I could fire the bottle directly.

I’d think that I’d need uber long pull cables if I mounted the bottle in the trunk. Obviously that isn’t a problem for an electrical fire system.[/quote]

Pegasus sells a 12’ pull cable. I just bought one because I’m relocating my pull handle to the dash and my suppression bottle is in the trunk.

I also have a fire extinguisher in the trunk, but don’t anyone borrow it to put out a fire because it’s full of nitrous.

#19

That is good to know. I’d have to get two pull handles, but I might just relocate the bottle to the trunk. Gotta think about that one…

#20

Ranger wrote:

My second fire bottle contains 4 liters of sand. Since my first one meets the rules requirements, the extinguising agent in the second one is my choice. Who says the ballast rules are too restrictive. :laugh:

Steve D.